Ebb and Flow and NFT Systems for Hydroponic Farming
Introduction to the NFT System
The NFT (Nutrient Film Technique) is a high yield technology crop production system, and requires both skill and experience from its users if the best results are to be obtained.
NFT Farming achieves high production and product quality through its effects on crop nutrition and water relations and by providing its users with additional opportunities to influence plant growth and development in more productive ways than can be achieved in older types of conventional culture. A thorough knowledge of crop cultural practices and especially of environmental control is needed, and NFT Farming of itself will not overcome deficiencies in the users knowledge in these areas. Hydroponic Farming allows for the prospect of changing from conventional culture methods such as growing in soil to the NFT system.
Best results for NFT Farming will be obtained in Greenhouses with good environmental control systems. For Hydroponic Farming, soil quality and fertility is of no consequence, and Ebb and Flow and NFT are suitable for use in older greenhouses where soil has been damaged by disease or mismanagement. The cost of operating NFT systems is increased when water of low quality is used.
Every Hydroponic Farming with an NFT and/or Ebb and Flow installation contains channels or gullies in which the plants grow in a shallow film of flowing nutrient solution. NFT gullies are usually, but not always, folded lengths of black and white polythene. The nutrient solution flows out of the ends of the gullies into collecting pipes and from the pipes into a sump. Pumps are used to circulate the solution from the sump through flow mains and headers into the gullies.
For Hydroponic Farming, the Nutrient Film Technique and Ebb and Flow is one of the oldest methods for growing and was heavily incorporated into the ancient Hanging Gardens of Babylon.
NFT systems are fairly inexpensive to purchase/build and can be easily assembled. Moreover, they do not require very powerful pumps relative to size, though the pumps will be running continuously (24/7). They perform quite well with a wide variety of vegetable crops when environmental conditions are right, but may experience issues with clogging in the irrigation manifold and must be checked. The shallow film of water also normalizes with the ambient temperature readily and is virtually impossible to heat or cool efficiently under extreme environmental conditions.
In nature, NFT Farming would be the equivalent of plants growing on a shallow river/stream or its banks. The roots are constantly wet, but their shallow position and the turbulence of the water keep them aerated and happy.